Device for driving in rotation a driven shaft from a driving shaft



M. LANG DEVICE FOR DRIVING IN ROTATION A DRIVEN SHAFT FROM A DRIVING SHAFT Original Filed Nov. 25, 1960 4 Sheets-Sheet 1 Fig. I

CUTTING DEV/CE REVERSER RELAY COUPLING/R DEV/CE Aug. 2, 1966 M. LANGE 3,263,514

DEVICE FOR DRIVING IN ROTATION A DRIVEN SHAFT FROM A DRIVING SHAFT Original Filed Nov. 25, 1960 Y 4 Sheets-Sheet 2 Aug. 2, 1966 M. LANGE 3,263,514

DEVICE FOR DRIVING IN ROTATION A DRIVEN SHAFT FROM A DRIVING SHAFT Original Filed Nov. 25, 1960 4 Sheets-Sheet 5 Aug. 2, 1966 M. LANGE 3,263,514

DEVICE FOR DRIVING IN ROTATION A DRIVEN SHAFT FROM A DRIVING SHAFT ()rlginal Filed Nov. 25, 1960 4 Sheets-Sheet 4 Fig 5 United States Patent 3,263,514 DEVICE FOR DRIVING 1N ROTATION A DRIVEN SHAFT FROM A DRIVING SHAFT Maurice Lange, Issy-les-Mouiineaux, France, assignor to Socit anonyme Ancienne Maison Turquetil, Ivry, France, a French society Original application Nov. 25, 1960, Ser. No. 71,573, new Patent No. 3,194,881, dated July 13, 1965. Divided and this application Jan. 13, 1965, Ser. No. 428,011 4 Claims. (Cl. 74-69) This application is a divisional application of my earlier application Ser. No. 71,573, filed November 25, 1960, now Patent No. 3,194,881.

The invention according to the present application relates to methods and devices for driving in rotation a driven shaft from a driving shaft. Such devices and methods are applicable in automatic engraving operations.

In engraving apparatus of a general type, the surfaces of the master pattern and of the work on which the engraved pattern is to be produced may be flat surfaces; and the scanning movements of a photoelectric scanner and of a cutter tool device with respect to the respective surfaces are then described along zigzag paths. However, in one frequently used construction both the master pattern surface and the work surface are cylindrical surfaces. In this case, the scanning movements with respect to such surfaces are obtained by rapidly rotating the respective cylinders about their axes, and simultaneously producing slow relative axial displacements between each cylinder and the related electromagnetic scanner or cutter tool devices respectively, the resulting scanning paths then being helical. In this case, the following difficulty is encountered. The master pattern is usually provided in the form of a printed sheet mounted on the surface of the master cylinder, with the upper and lower side edges of the sheet lying adjacent to each other to form a seam extending along a generatrix of the cylinder. A discontinuous line is thus present at this generatrix and produces a corresponding discontinuity in the engraved pattern formed on the cylindrical work surface. Various expedients have been proposed to eliminate this discontinuity, but all have been mechanically complicated and unsatisfactory in operation.

It is an object of this invention to provide a relatively simple, and highly eifective, mechanism for positively eliminating the discontinuous effect of the adjacent sides of a cylindrical master pattern in a cylindrical engraving process.

More generally, it is a further object of the invention to provide means for synchronizing the drive between a driven shaft and a driving shaft, such as between the master cylinder and the work cylinder of an engraving apparatus, so that the driven shaft is halted during a par ticular time period, for instance, when the seam is scanned, and is increased in speed during other times, such that for each complete rotation of the driving shaft a complete rotation of the driven shaft will be obtained.

In accordance with a feature of the invention there is provided variaible coupling means connecting the driving and driven shafts for arresting the rotation of the driven shaft during a particular fraction of each revolution of the driving shaft and for increasing the speed of rotation of the driven shaft in excess of that of the driving shaft throughout the remainder of each revolution such that the driven shaft undergoes one complete revolution for each revolution of the driving shaft.

A particular feature concerns the adjustability of the coupling means when used in engraving apparatus to vary the period of time during which the driven shaft is arrested in order to correspond precisely with the tim during which the photoelectric cell will scan the seam. Thus the coupling means is adapted for use with a multitude of patterns in which the seam varies from one pattern to another.

By virtue of the above arrangement, the period in which the seam is scanned is effectively eliminated from the work cylinder, while the remaining period of scanning is slightly accelerated on the work cylinder so as to compensate for the eliminated period and thereby provide a pattern substantially corresponding with that on the master pattern and without the seam.

Further objects and features of the invention will become apparent from the following description given by way of illustration with reference to the attached drawing, wherein:

FIGURE 1 is a diagrammatic plan view of engraving apparatus utilizing a devic according to the invention;

FIGURE 2 is a sectional view taken along line 22 in FIG. 4, showing only a portion of the device for purposes of clarification, in which the device is in one particular position of operation;

FIGURE 3 shows the device in FIG. 2 in a second position of operation;

FIGURE 4 is a side sectional view of a portion of the apparatus diagrammatically shown in FIG. 1, and

FIGURE 5 is a sectional view taken along line VV in FIG. 4.

Referring to the drawing, therein is shown an embodiment of the invention adapted for the engraving of cylindrical patterns, as used, for example, for continuous printing on paper and fabric webs. In such continuous printing, difficulties have heretofore been encountered for suppressing an objectionable connecting line which occurs at each revolution of the pattern cylinder. This will be better understood from a description of a cylindrical pattern engraving apparatus such as that shown in FIG. 1.

As shown in FIGURE 1, the apparatus of generally conventional type comprises a pair of cylinders 51 and 63 secured on a pair of aligned, rotatable shafts 201 and 202 respectively. The shafts 201 and 202 are interconnected by way of a variable coupling mechanism schematically shown at 65 which will be described in detail hereinafter. For purposes of preliminary explanation it may be assumed that the variable coupling 65 is absent and that both shafts 261 and 202 are bodily rotated together. Shaft 201 is driven from a prime mover through means diagrammatically indicated at 53.

Cylinder 51 is a master cylinder which carries around its periphery a pattern sheet, e.g., a printed or hand-drawn sheet having a desired pattern thereon, and it is this pattern that is to be reproduced, by means of cutter tool 61, upon the surface of th work cylinder 63, which may be, for example, wood or metal. It will be understood that after the cylinder 63 has thus been provided with the engraved pattern thereon, it is removed from the apparatus shown and constitutes a printing cylinder which will serve to reproduce the same pattern on a web of material by means of continuous printing apparatus of conventional type.

Refer-ring again to FIGURE 1, the apparatus comprises a scanner diagrammatically shown as including a lens 54 scanning the surface of cylinder 51 and a photo-cell 55 which produces a varying electric output depending on the cell illumination. The scanner device is preferably though not necessarily similar to that described with reference to the scanner device in my earlier application. The photocell output is passed through an amplifier 56 to a reverse-r relay device which may be similar to that shown in my earlier application in FIGURE 10 thereof. The relay device is connected to reversibly energize the electromagnet system 9192, which may be similar to the electromaignet system in my earlier application as shown in FIGURES 8 and 9, and thereby actuate the cutter tool 61 towards and away from the surface of cylinder 63, i.e. between an operative cutting position and an idle position.

Thus, depending on the particular portion of the pattern on the cylinder 51 which is being scanned by scanner 54, the photocell 55 will receive a light impulse which will control the position of cutter tool 61. The cutter tool is driven in high-speed rotation through a pulley 62. The relative axial scanning displacement between master pattern cylinder 51 and scanner unit 5455 is produced by imparting a slow axial movement to the scanner in the direction of .arrow 66, while the cylinder structure remains in fixed axial position, so that the scanner scans the pattern on cylinder 51 along a helical path of small pitch. The tool assembly including cutter 61 is axially displaced at a corresponding slow rate relative to the cylinder 63 in the direction of arrow 67, i.e. reverse from the direction of axial displacement of the scanner. This is effected since it is desired to obtain on cylinder 63 an engraved pattern which is inverted with respect to the master pattern, on cylinder 51, since the said engraved pattern is to serve in turn as a printing pattern in subsequent printing operations. It will be understood that under other circumstances, both the displacements of the scanner assembly and the engraving tool assembly may well be effected in the same direction if desired. Also, each of the relative scanning displacements may be effected otherwise than in the manner shown, and for instance may be obtained by axial displacement of the cylinder past a stationary assembly.

It will be appreciated that in the operation of the apparatus of FIGURE 1 for engraving on work cylinder 63 a pattern corresponding to the printed master pattern on master cylinder 51, once every revolution of master cylinder 51 the scanner unit 54-55 will necessarily sense the passing of the connection or seam between the adjacent edges of the pattern sheet wound around cylinder 51, and will emit a corresponding signal to actuate the cutter tool 61 in one or the other opposite direction, whereby an objectionable mark will appear on the engraved pattern and will be transferred therefrom to all the material subsequently printed therefrom. Various expedients have been proposed heretofore for eliminating this objectionable mark, as by using expansible cylinders or the like. These expedients have involved consider-able complications in the construction, operation and adjustment of the apparatus and have not proven really satisfactory. According to the invention, this problem is solved by the interposition in the drive from the master to the work cylinders 51, 63 of a variable coupling 65 which acts automatically to arrest the rotation of work cylinder 63 for a fraction of each revolution as the afore-mentioned seam or connecting line is moving past the scanner, and to increase the rate of rotation of said work cylinder over the remainder of its revolution so as to compensate for the momentary arrest in its rotation and thereby preserve the requisite over-all synchronism between the two cylinders.

Referring to FIGURES 24, the coupling means 65 is shown as interposed in the drive from drive shaft 201 to driven shaft 202. Shaft 201 is formed with an extension 203 of reduced diameter formed in turn with an end center point 204 which engages a center socket in the end face of shaft 202 for precise alignment between the shafts. Secured on drive shaft section 203 by means of a grub screw 205 is a sleeve 206 having a flange 207 at its outer end. A screw pivot 208 threaded in flange 207 at a predetermined radial distance from the center of flange 207 .as clearly shown in FIGURES 2 and 3 serves fixedly to support a fork member 209 in an adjusted angular position thereon by means of bolt A. As will appear later, the angular set-ting of the fork member 209 by loosening bolt A permits the adjusting of the duration of the time period, in each revolution, that the rotation of the driven shaft is to be arrested.

Surrounding the drive shaft section 203 and sleeve 206 rotatable therewith, is a stationary sleeve 210 which forms part of the stationary apparatus frame C. Sleeve 210 in effect constitutes a smooth bearing for the drive shaft section 203, and is shown as provided with lubricator ports one of which is shown at 211. Secured in axially spaced relationship on the exterior of sleeve 210, in the area thereof surrounding sleeve 206, are a pair of cam members 212 and 213, which extend in parallel planes normal to the general axis of shaft rotation, and are, in the illustrated embodiment, formed with Archimedean spiral contours as clearly shown in FIGURES 2 and 3. The cam members 212, 213 may be secured to sleeve 210 in conventional manner, as for example, by bolts B.

Secured in fixed radial position on the end section 202 of the driven shaft, is a fork member 217. A rod 216, as for example, the screw rod as shown, carries a pair of slider members 218 .and 219 thereon, which are arranged to be respectively positioned in .the slots defined between the tines of fork members 209 and 217 and in sliding relationship therewith. The rod 216 further carries a pair of spaced bearings 214 and 215 forming carn follower rollers in engagement with the respective spiral cam surfaces 212 and 213. Means are provided for resiliently retaining the cam follower rollers 214, 215 in engagement with the cam surfaces. For this purpose, there is employed a grooved pulley-like member 220 rotatably surrounding the sleeve 210 and a helical spring E having its ends connected to form a loop. The spring E is passed around the groove in member 220 and extends to encompass a sleeve 221 surrounding rod 216 and extending between the follower bearings 214, 215; thereby providing the desired resilient retaining action.

In the operation of this device, it is assumed that the drive shaft 201 is revolving in the direction of arrow 223. FIGURE 2 shows a position in a revolution of the drive shaft, in which coupling rod 216 has just moved past the radial segment connecting the small and large radius ends of the spiral cam surfaces, and is being held at a minimum radial distance from the shaft axis by the cam contour. The rod 216 acts as a variable drive coupling interconnecting the forks 209 and 217 and the shafts 201, 202 respectively secured thereto, so that the driven shaft 202 revolves at a variable angular velocity all times higher, throughout the revolution, than the angular velocity of the drive shaft 201. As the driven shaft completes its revolution with the coupling rod 216 positioned at the maximum radius of the spiral cam surface (see FIG- URE 3), it stops rotating While the drive shaft with its associated fork 209 completes its revolution to be restored to the position of FIGURE 2, while the rod 216 slides down the slot in the now stationary fork 217. In other words, the driven shaft runs faster than the drive shaft over the greater part of each revolution and then stops and waits for the drive shaft to catch up with it. Thus over-all synchronism between the shaft is preserved.

The magnitude of angular displacement of the drive shaft during the stationary condition of the driven shaft is adjustable by setting the angular position of the fork 209 on flange 207. For this purpose a calibration 222 on the flange 207 cooperates with an index on the fork 209 to facilitate this angular setting adjustment. It will be readily seen that when the fork 209 is set to a radial position on flange 207 the stationary period of the driven shaft is reduced to zero, and both shafts will revolve continually at the same velocity, whereas with fork 209 adjusted to a position approaching right angles to the radius of the flange, the driven shaft remains stationary throughout a portion of each drive shaft revolution, and revolves very fast in the intervening periods.

The mechanism described may be modified in various ways while still retaining the operating principle disclosed. Thus, the fixed inclination radial fork 217 may be attached to the drive shaft, and the adjustable fork 209 to the driven shaft; the fixed fork 217 need not necessarily be radially positioned, but may extend at an angle. Furthermore, both forks may be provided with adjustment in an angular position. The cam surfaces 212, 213, need not necessarily be two in number, and a single cam surface may be used. Moreover, the cam counter may differ from the spiral shown.

It will be understood that in the operation of the apparatus of FIGURE 1 provided with a variable drive coupling 65 of the type described with reference to FIG- URES 2-4, the master pattern sheet is placed around the master cylinder 51 in such a manner that the seam moves past the scanner device during the stationary period of the driven shaft carrying cylinder 63. Thus the effect of the passage of the seam past the scanning device will not be transferred in the form of a mark on the engraved pattern on cylinder 63. Preferably, means is provided for retracting the cutter tool 61 from the surface of cylinder 63 during the stationary period of the cylinder. Such means, not shown, may for instance include a contact actuated by rod 216 as it reaches the large-radius end of the cam surface 212, 213 for actuating the electromagnets, of the cutter assembly to retract the tool.

The apparatus of the invention has been successfully used in the engraving of wood pattern cylinders using a considerable depth of cut. The apparatus has also been applied to metal cylinders, and may serve to produce extremely fine patterns thereon; the helical pitch of the scanning path can be made extremely small, thereby to increase the fineness of the reproducible patterns, while still working considerably faster than with conventional apparatus.

Numerous modifications and variations of the disclosed embodiment will become apparent to those skilled in the art without departing from the scope and spirit of the invention as defined in the following claims.

What is claimed is:

1. A device for driving in rotation a driven shaft from a driving shaft, said device comprising: variable coupling means connecting said shafts for arresting the rotation of the driven shaft during a predetermined fraction of each revolution of the driving shaft and for increasing the speed of rotation of the driven shaft over that of the driving shaft throughout the remainder of each revolution such that the driven shaft undergoes one complete revolution for each revolution of the driving shaft, said variable coupling means comprising drive means rotatable with the driving shaft and driven means coaxially aligned with the drive means and rotatable with the driven shaft, a coupling rod member extending generally parallel to the common axis of said drive and driven means at a variable radial distance from said axis, a first constraining member rotatable with the drive means and engageable with the rod member for constraining the rod member to follow a predetermined linear path of relative motion with respect to the drive means, a second constraining member rotatable with the driven means and engageable with the rod member for constraining the rod member to follow a predetermined linear path of relative motion with respect to the driven means, the position of at least one of said constraining members being adjustable to adjust the angular setting of the related linear path with respect to a radius of the related drive or driven means, and cam means engageable with the rod member for cyclically varying the radial distance thereof from said common axis throughout each revolution of said drive and driven means.

2. A device for driving in rotation a driven shaft from a driving shaft, said device comprising: variable coupling means connecting said shafts for arresting the rotation of the driven shaft during a predetermined fraction of each revolution of the driving shaft and for increasing the speed of rotation of the driven shaft over that of the driving shaft throughout the remainder of each revolution such that the driven shaft undergoes one complete revolution for each revolution of the driving shaft, said variable coupling means comprising a drive member rotatable with the driving shaft and a driven member coaxially aligned with the drive member and rotatable with the driven shaft, a coupling rod member extending generally parallel to the common axis of said drive and driven members at a variable radial distance from said axis, a first fork member rotatable with the drive means and engageable around the rod member for constraining the rod member to follow a predetermined linear path of motion with respect to the drive member, a second fork member rotatable with the driven member and engageable around the rod member for constraining the rod member to follow a predetermined linear path of relative motion with respect to the driven member, the position of at least one of said fork members being adjustable to adjust the angular setting of the related linear path with respect to a radius of the related drive or driven member, and a stationary cam having a surface of generally varying radial distance from said common axis and which varies from a minimum to a maximum value throughout each revolution of said drive and driven members.

3. A device according to claim 2, wherein said second fork member is positioned radially with respect to said driven member, and said coupling means further comprises means supporting said first fork member in angularly settable relation from said drive member with respect to a radial line of the drive member.

4. A device according to claim 3 in which the surface of the cam is an Archimedes spiral.

References Cited by the Examiner UNITED STATES PATENTS 2,159,372 5/1939 Brosch 7463 2,206,942 7/1940 Cook 13 2,222,069 7/1940 Cook 90-13 2,498,036 2/1950 Grace 74393 2,922,313 1/1960 Penny 74-393 MILTON KAUFMAN, Primary Examiner.

BROUGHTON G. DURHAM, Examiner.

F. E. BAKER, Assistant Examiner. 

1. A DEVICE FOR DRIVING IN ROTATION A DRIVEN SHAFT FROM A DRIVING SHAFT, SAID DEVICE COMPRISING: VARIABLE COUPLING MEANS CONNECTING SAID SHAFTS FOR ARRESTING THE ROTATION OF THE DRIVEN SHAFT DURING A PREDETERMINED FRACTION OF EACH REVOLUTION OF THE DRIVING SHAFT AND FOR INCREASING THE SPEED OF ROTATION OF THE DRIVEN SHAFT OVER THAT OF THE DRIVING SHAFT THROUGHOUT THE REMAINDER OF EACH REVOLUTION SUCH THAT THE DRIVEN SHAFT UNDERGOES ONE COMPLETE REVOLUTION FOR EACH REVOLUTION OF THE DRIVING SHAFT, SAID VARABLE COUPLING MEANS COMPRISING DRIVE MEANS ROTATABLE WITH THE DRIVING SHAFT AND DRIVEN MEANS COAXIALLY ALIGNED WITH THE DRIVE MEANS AND ROTATABLE WITH THE DRIVEN SHAFT, A COUPLING ROD MEMBER EXTENDING GENERALLY PARALLEL TO THE COMMON AXIS OF SAID DRIVE AND DRIVEN MEANS AT A VARIABLE RADIAL DISTANCE FROM SAID AXIS, A FIRST CONSTRAINING MEMBER ROTATABLE WITH THE DRIVE MEANS AND ENGAGEABLE WITH THE ROD MEMBER FOR CONSTRAINING THE ROD MEMBER TO FOLLOW A PREDETERMINED LINEAR PATH OF RELATIVE MOTION WITH RESPECT TO THE DRIVE MEANS, A SECOND CONSTRAINING MEMBER ROTATABLE WITH THE DRIVEN MEANS AND ENGAGEABLE WITH THE ROD MEMBER FOR CONSTRAINING THE ROD MEMBER TO FOLLOW A PREDETERMINED LINEAR PATH OF RELATIVE MOTION WITH RESPECT TO THE DRIVEN MEANS, THE POSITION OF AT LEAST ONE OF SAID CONSTRAINING MEMBERS BEING ADJUSTABLE TO ADJUST THE ANGULAR SETTING OF THE RELATED LINEAR PATH WITH RESPECT TO A RADIUS OF THE RELATED DRIVE OR DRIVEN MEANS, AND CAM MEANS ENGAGEABLE WITH THE ROD MEMBER FOR CYCLICALLY VARYING THE RADIAL DISTANCE THEREOF FROM SAID COMMON AXIS THROUGHOUT EACH REVOLUTION OF SAID DRIVE AND DRIVEN MEANS. 